Press pressure and closed position control

ABSTRACT

A mechanically actuated press in which actuating means has a predetermined stroke normally effective to move a die or the like into a predetermined position relative to a work support or second die. The actuating means is extensible, such for example as a toggle, and acts between the movable die and a prestressed resilient abutment to limit the application of pressure.

United States Patent [191' Baldyga PRESS PRESSURE AND CLOSED POSITION CONTROL [75] Inventor: Joseph W. Baldyga, Mt. Clemens,

Mich.

[73] Assigne: Diamond Die & Mold Co., Mt.

Clemens, Mich.

[22] Filed: Nov. 29, 1971 [21] Appl. No.: 202,896

[52] US. Cl 72/431, 72/451, 100/272, 100/296 [51] Int. Cl B2lj 9/18 [58] Field of Search..... 72/431, 451, 433, 432, 465, 72/466, 450; 100/286, 272, 296

[56] References Cited UNITED STATES PATENTS 2,784,665 3/1957 Georgeff lOO/53 [4 1 Feb. 12, 1974 322,930 7/1885 Hammond 72/431 463,160 11/1891 Moore IOU/272 3,271,989 9/1966 Paddock 72/451 3,374,657 3/1968 Baldyga 72/451 Primary Examiner-Charles W. Lanham Assistant Examiner-Gene P. Crosby Attorney, Agent, or FirmWhittemore, l-lulbert &

Belknap 57 ABSTRACT A mechanically actuated press in which actuating means has a predetermined stroke normally effective to move a die or the like into a predetermined position relative to a work support or second die. The actuating means is extensible, such for example as a toggle, and acts between the movable die and a prestressed resilient abutment to limit the application of pressure.

9 Claims, 5 Drawing Figures PRESS PRESSURE AND CLOSED POSITION CONTROL BRIEF SUMMARY OF THE INVENTION v In mechanically actuated dies, in which a ram is movable in a fixed stroke, the stroke can normally be adjusted so that at the point of closest approach, tooling carried by the ram is spaced a precisely predetermined distance from the work support.

A typical example of an application of this structure is a die for crimping electrical connectors to the end of conductors, such for example as stranded conductors. The strokeof the ram can be adjusted so that for a particular size of electrical conductor and connector a precisely predetermined crimping pressure may be applied. However, variations in size may occur such for example as may occur when all strands of a stranded conductor are at the upper limit of their acceptable range of diameter. If the work piece is lightly oversized, and if the die is caused to move to an exact spacing with reference to the work support irrespective of any pressures which may be required, the result may be fracture of the threads by excessive pressure. Similarly, if the assembly of parts is undersize there may insufficient holding action when the connector is crimped in place.

In order to limit pressure to a predetermined maximum, yieldable resilient means is interposed between the work support or the tooling support and the rigid frame or support structure. Accordingly, when predetermined pressure is exceeded, the yieldable resilient means yields and will limit the pressure applied to a value determined essentially by the prestressing of the resilient means.

To insure against insufficient pressure application in the operation, the parts may be adjusted so that the resilient yieldable means is caused to yield even when the work assembly is undersize. Thus, the application of pressure will be essentially determined by the prestressingv applied to the yieldable means.

BRIEF DESCRIPTION OF TI-IE DRAWINGS I FIG. 1 is a fragmentary sectional view showing the press. I

FIG. 2is a section on the line 2 .2, FIG. 1.

FIG. 3 is an elevational viewshowing the coaction between a work support and tooling carried by the press.

FIG. 4 is a fragmentary view illustraing a different embodiment of yieldable means associated with the press.

FIG. 5 is a sectional view through a non-adjustable prestressed capsule.

DETAILED DESCRIPTION The present invention is illustrated as applied to a press which includes a rigid frame or support structure including a forwardly extending arm 12 overlying work support structure more or less diagrammatically illustrated at 14 in FIG. 3. The work support structure is shown as carried by a bed or table 16 which may be a part of the frame 10 or may be a rigid support on which the frame is mounted.

The forwardly extending arm 12 includes a pair of laterally extending ears 18 provided with bushings 20 which receive guide pins 22 as will later be described. The interior of the frame 10 including the arm 12 is open and the forward end of the arm 12 is closed by a wall 24.

At its upper portion, the forward end of the arm 12 is formed with an upwardly open cylindrical recess or cylinder 26, the lower end of which is provided with stops or abutments 28. Vertically movable within the cylinder 26 is a cup-shaped piston 30 the bottom end of which is closed as illustrated, and the upper end of which is open to receive an adjustable prestressing member 32. The upper end of the cylinder 26 is closed by a cap 34 which may be bolted or otherwise secured thereto and which receives an adjustable threaded element 36 which engages the upper end of the prestressing member 32.

Received within the cup below the prestressing member 32 is yieldable resilient means which in FIG. 2 is illustrated as comprising a block 38 of resilient yieldable material such for example as urethane rubber. The block 28 is smaller in cross-section than the interior of the cup 30 so that resilient yielding of the cup is permitted under conditions which will later be described. This is necessary because of the fact that the urethane, while yieldable and resilient, is not materially compressible.

It will be observed that by screwing the threaded element 36 downwardly, a predetermined prestressing is applied to the cup 30 urging it downwardly against the stops 28. Accordingly, upward movement of the cup 30 is prevented until forces are applied thereto in excess of the prestressing force applied by the block 38.

At its underside the cup 30 is provided with ears 40 apertured to receive a pin 42 by means of which a plurality of upper toggle links 44 are pivotally connected. Lower toggle links 46 are connected to the upper toggle links 44 by a pivot pin 48 and are connected to a tooling head 50 by a pin 52.

Connected to the pin 48 are elongated toggle links 54 which are connected by a pin 56 to relatively short toggle links 58. The links 58 in turn are connected to a pin 60 mounted in a fixed position on the frame or rigid support structure 10.

Also connected to the pin 56 which interconnects the toggle links 54 and 58 are links 62 which are connected by a crank pin.64 to an actuating crank 66.

In operation, the crank 66 is given a single complete rotation from approximately the position illustrated in FIG. 1, which will have the effect of drawing the link 62 downwardly by a crank action which is capable of applying relatively great force through the link 62 to the pin 56 as the crank pin 64 moves through the position in which the pins 56 and 64 are at diametrically opposite sides of the axis 68 of the crank. The parts are so dimensioned that at .this time the toggle made up of the links 54 and 58 is straightened out and accordingly the force is applied to the pin 48 which is greatly multiplied with reference to the force transmitted through the link 62. As the toggle made up of the links 54 and 58 assumes a straight line condition, so too does the toggle made up of the links 44 and 46. Accordingly, the tooling head 50 is move downwardly to a limiting position and is capable of applying forces of relatively great magnitude.

From the foregoing it will be observed that the mechanical actuating means for moving thetool or die support or head downwardly has a fixed stroke and the lowermost position of the die head is normally determined by the spacing between the pins 42 and 52 when the toggle linkage is straight and the pin 48 is in line between the pins 42 and 52.

As illustrated in FIG. 3, suitable tooling indicated generally at 70 is adapted to be attached to the tooling head by a T-shaped support 72 adapted to be received in a T-shaped recess 74 provided in the tooling head.

As seen in this Figure, a work piece is diagrammatically indicated at W and may be assumed to be an electrical conductor to which a connector is crimped between a work support die 76 and a forming die 78.

In order to compensate for variations in size of the assembled components of the workpiece, the press is adjusted so that when all toggles and cranks are in limiting position, the die 78 is either in the desired lower position to cooperate with the usual size of work piece, or slightly below this position.

If an oversized work piece is interposed between the die elements, excessive pressure will be developed and this is limited by the prestressing of the block 38. It will be apparent that as a predetermined pressure is exceeded the tool head 50 may move to a position short of its normal lowermost position as a result of upward sliding of the cup-shaped piston 30 in the cylinder 26.

As previously suggested, the parts may'be adjusted so that even for work assemblies which are slightly undersize, the stroke of the die head 50 is such that a pressure is achieved sufficient to result in displacement of the cup 30 upwardly from the stop 38 and thus to apply a pressure to the work assembly which is essentially determined by the prestressing load applied to the block 38.

While of course there will be a minor increase in pressure dependent upon the amount of displacement of the cup 30, this is negligible and for all practical purposes the crimping pressure is determined by the prestressing or pre-compression of the block 38.

It will of course be apparent that equivalent results would be obtained by providing the upper pin 42 in a fixed position relative to the frame or rigid support structure and by providing the yieldable structure in association with the lower work support 14.

Referring now to FIG. 4 there is illustrated a modification of the present invention in which, instead of the block of yieldable resilient material 38, there is provided an assembly of Belleville springs as indicated at 80. These are associated with the cup-shaped piston 30 as before, and the prestressing applied to the springs is applied through the prestressing member 32 movable downwardly into the cup by the threaded adjusting element 36.

Instead of providing for variation in prestressing pressure applied to the block 36 or spring assembly 80, a prestressed capsule may be interposed between the frame and die actuator. In this case of course, the capsule has a stated yield strength and is not adjustable.

Such an arrangement is diagrammatically illustrated in FIG. 5 in which the cup-shaped member 86 receives the yieldable resilient block 88 which again, may be formed of a resilient material such as urethane, neoprene, or the like. The cup 86 is provided with a closure 90, the underside of which engages the resilient block 88 to apply a predetermined prestressing force thereto. Cooperating abutments indicated at 92 and 94 on the cup and closure retain the closure in the illustrated po- 6 gagement and disengagement by partial relative rotation between the cup and closure. What I claim as my invention is: l. A press for applying pressure to a work piece com- 5 prising rigid support structure,

a stationary member carried by said support structure, v

a movable member carried by said support structure for movement toward and away from said stationary member,

positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply a pressure to a work piece interposed between said members,

yieldable means interposed between said positive acting mechanical actuating means and said rigid support structure and prestressed a predetermined amount to yield initially only when a predetermined force on the work piece is reached and to provide an opposing force which increases in accordance with the amount by which said yieldable means yields.

said yieldable means comprising a container including a first wall,

a closure for said container including a second wall movable while in closing relation toward and away from said first wall,

solid yieldable means within said container,

and means limiting movement of said closure away from said first wall of said container to maintain the predetermined pre-stress on said solid yieldable means.

2. A press comprising rigid support structure, a work support member mounted in fixed position on said structure, guide means on said structure, a tooling support member associated with said guide means for guided movement toward and away from said work support member, a prestressed yieldable abutment on said rigid support structure, and extensible actuating means interposed between said yieldable abutment and said tooling support member, said yieldable abutment comprising a cylinder in said rigid support structure in alignment with said work support member, a cupshaped piston slidable in said cylinder, a stop in said cylinder limiting movement of said piston toward said work support member, resilient means in said cupshaped piston, and an adjustable element carried by said rigid support structure and movable into said cup to apply a predetermined prestress to said resilient means.

3. A press as defined in claim 2 in which said yieldable abutment comprises a block of yieldable highly re-' silient material.

4. A press as defined in claim 2 in which said yieldable abutment comprises an assembly of Belleville springs.

5. A press as defined in claim 2 in which said actuating means comprises a toggle.

6. A press for applying pressure to a work piece comprising rigid support structure,

a stationary member carried by said support structure,

a movable member carried by said support structure for movement towardand away from said stationary member,

positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply a pressure to a work piece interposed between said members,

yieldable means interposed between one of said members and said rigid support structure and prestressed a predetermined amount to yield only when a predetermined force on the work piece is exceeded,

said yieldable means comprising a container including a first wall,

a closure for said container including a second wall movable while in closing relation toward and away from said first wall,

solid yieldable means withinsaid container,

and means limiting movement of said closure away from said first wall of said container to maintain the predetermined pre-stress on said solid yieldable means,

said solid yieldable means comprising a block of substantially incompressible yieldable highly resilient material dimensioned to provide space within said container for resilient distortion thereof.

7. A press as defined in claim 1 in which the solid yieldable means comprises an assembly of Belleville springs within said container.

8. A press for applying pressure to a work piece comprising rigid support structure,

a stationary member carried by said support structure,

a movable member carried by said support structure for movement toward and away from said stationary member,

positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply apressure to a work piece interposed between said members,

yieldable means interposed between one of said members and said rigid support structure and prestressed a predetermined amount to yield only when a predetermined force on the work piece is exceeded,

said yieldable means comprising a container including a first wall,

a closure for said container including a second wall movable while in closing relation toward and away from said first wall,

solid yieldable means within said container,

means limiting movement of said closure away from said first wall of said container to maintain the predetermined prestress on said solid yieldable means,

and adjustable means on said support engaging said closure and operable to move said closure toward said first wall to vary the amount of pre-stress.

9. A press for applying pressure to a work piece comprising rigid support structure,

a stationary member carried by said support structure,

a movable member carried by said support structure for movement toward and away from said stationary member,

positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply a pressure to a work piece interposed between said members,

yieldable means interposed between one of said members and said rigid support structure and prestressed a predetermined amount .to yield only when a predetermined force on the work piece is exceeded,

said yieldable means comprising a container including a first wall,

a closure for said container including a second wall movable while in closing relation toward and away from said first wall,

solid yieldable means within said container,

and means limiting movement of said closure away from said first wall of said container to maintain the predetermined pre-stress on said solid yieldable means,

said container and closure together constituting a capsule, and means on said container and closure cooperating to limit movement of said closure away from said first wall to determine the amount of pre-stress. 

1. A press for applying pressure to a work piece comprising rigid support structure, a stationary member carried by said support structure, a movable member carried by said support structure for movement toward and away from said stationary member, positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply a pressure to a work piece interposed between said members, yieldable means interposed between said positive acting mechanical actuating means and said rigid support structure and prestressed a predetermined amount to yield initially only when a predetermined force on the work piece is reached and to provide an opposing force which increases in accordance with the amount by which said yieldable means yields. said yieldable means comprising a container including a fIrst wall, a closure for said container including a second wall movable while in closing relation toward and away from said first wall, solid yieldable means within said container, and means limiting movement of said closure away from said first wall of said container to maintain the predetermined pre-stress on said solid yieldable means.
 2. A press comprising rigid support structure, a work support member mounted in fixed position on said structure, guide means on said structure, a tooling support member associated with said guide means for guided movement toward and away from said work support member, a prestressed yieldable abutment on said rigid support structure, and extensible actuating means interposed between said yieldable abutment and said tooling support member, said yieldable abutment comprising a cylinder in said rigid support structure in alignment with said work support member, a cup-shaped piston slidable in said cylinder, a stop in said cylinder limiting movement of said piston toward said work support member, resilient means in said cup-shaped piston, and an adjustable element carried by said rigid support structure and movable into said cup to apply a predetermined prestress to said resilient means.
 3. A press as defined in claim 2 in which said yieldable abutment comprises a block of yieldable highly resilient material.
 4. A press as defined in claim 2 in which said yieldable abutment comprises an assembly of Belleville springs.
 5. A press as defined in claim 2 in which said actuating means comprises a toggle.
 6. A press for applying pressure to a work piece comprising rigid support structure, a stationary member carried by said support structure, a movable member carried by said support structure for movement toward and away from said stationary member, positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply a pressure to a work piece interposed between said members, yieldable means interposed between one of said members and said rigid support structure and prestressed a predetermined amount to yield only when a predetermined force on the work piece is exceeded, said yieldable means comprising a container including a first wall, a closure for said container including a second wall movable while in closing relation toward and away from said first wall, solid yieldable means within said container, and means limiting movement of said closure away from said first wall of said container to maintain the predetermined pre-stress on said solid yieldable means, said solid yieldable means comprising a block of substantially incompressible yieldable highly resilient material dimensioned to provide space within said container for resilient distortion thereof.
 7. A press as defined in claim 1 in which the solid yieldable means comprises an assembly of Belleville springs within said container.
 8. A press for applying pressure to a work piece comprising rigid support structure, a stationary member carried by said support structure, a movable member carried by said support structure for movement toward and away from said stationary member, positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply a pressure to a work piece interposed between said members, yieldable means interposed between one of said members and said rigid support structure and prestressed a predetermined amount to yield only when a predetermined force on the work piece is exceeded, said yieldable means comprising a container including a first wall, a closure for said container including a second wall movable while in closing relatiOn toward and away from said first wall, solid yieldable means within said container, means limiting movement of said closure away from said first wall of said container to maintain the predetermined prestress on said solid yieldable means, and adjustable means on said support engaging said closure and operable to move said closure toward said first wall to vary the amount of pre-stress.
 9. A press for applying pressure to a work piece comprising rigid support structure, a stationary member carried by said support structure, a movable member carried by said support structure for movement toward and away from said stationary member, positive acting mechanical actuating means connected to said movable member and having a fixed stroke normally operable to provide movement of said movable member into predetermined spacing from said stationary member to apply a pressure to a work piece interposed between said members, yieldable means interposed between one of said members and said rigid support structure and prestressed a predetermined amount to yield only when a predetermined force on the work piece is exceeded, said yieldable means comprising a container including a first wall, a closure for said container including a second wall movable while in closing relation toward and away from said first wall, solid yieldable means within said container, and means limiting movement of said closure away from said first wall of said container to maintain the predetermined pre-stress on said solid yieldable means, said container and closure together constituting a capsule, and means on said container and closure cooperating to limit movement of said closure away from said first wall to determine the amount of pre-stress. 